1. Field of the Invention
The present invention relates to microsurgical clamps for surgical attachment of blood vessel ends by suturing thereof.
2. The Prior Art
Microvascular surgical clamps for use in microscopic anastomosis of severed ends of blood vessels are well known in the art especially from the medical literature. As described in Ostrup, et al, 10 Plastic and Reconstructive Surgery 18-28, "Microvascular Surgery" (1976), joining of severed veins or artery ends by sutures is well established. Any of a number of double microvascular clamps described in the literature may be employed, including those of Acland, 75 Surgery 185, "Microvascular Anastomosis: a device for holding stay sutures and a new vascular clamp"; Henderson et al., Medical Journal of Australia (Apr. 4, 1970, pages 715-16), "An Adjustable Double Microvascular Clamp"; Zirkle, et al., 51 Plastic and Reconstructive Surgery 340-41, "An Adjustable Double Clamp for use in Microvascular Surgery", to clamp two blood vessel ends and to hold them in a desired relationship. Two stay sutures are placed through the front walls, 120.degree. apart, to join the vessel ends. Close sutures placed between the two stay sutures join the wall ends between the stay sutures. The double clamps are then rotated through 180.degree., with one stay suture passed over and one under the blood vessel. Then the other 240.degree. of the vessel wall is repaired with further sutures.
Of the clamps described in the Ostrup and other literature, only the Acland clamp shown in the 1974 Surgery article has a stay suture retention device. The Acland device has a pair of center-pivot type clamps held in spaced relation by crossed wires forming a nautical-type cleat about which the stay sutures are wrapped and jammed for retention. The Henderson clip has laterally separable clamps of a rear pivot type which are closed by screwing a threaded nut at the base of the jaws. A clamp by Buncke has angled clamps engaging a square shaft at an angle, but having substantially parallel jaws. Neither the Henderson nor the Buncke devices have stay suture retainers thereon. Surgeons employing such clamps must employ any of several methods for immobilizing the stay sutures with respect to the blood vessel during close suturing thereof, as described in the Ostrup article.
Of the prior patented art, U.S. Pat. No. 3,911,926 discloses an adjustable microvascular U-shaped clamp wherein a pair of Mayfield-type clamps are received about a bar having capped ends, the clamps being maintained in position by a covering thereover and a clamp opener engaged therewith. U.S. Pat. No. 3,509,882 shows a comparatively large, parallel-jaw spring clip, wherein a spring within a tubular body transverse to fixed amd movable jaws acts to close a vessel placed therebetween.
None of the prior patented or published art shows a microvascular surgical clamp having eight ideal features as identified in an article by Thurston, et al., Plastic and Reconstructive Surgery (February, 1976), at 202. Such features include small size, light weight, mechanical simplicity, flat jaws coated with a non-slip surface, maximum pressure of 30 grams per square centimeter together with an ability to be calibrated for lesser pressures, and durability for repeated use.